Polishing device



Nov. 15, 1966 e. w. GRAVES POLISHING DEVICE 2 Sheets-Sheet 1 Filed May25, 1964 Nov. 15, 1966 cs. w. GRAVES POLISHING DEVICE 2 Sheets-Sheet 2Filed May 25, 1964 United States Patent 3,284,961 POLISHING DEVICEGeorge W. Graves, Glenview, Ill., assignor to Buehler Ltd., Evanston,111., a corporation of Illinois Filed May 25, 1964, Ser. No. 369,995 4Claims. (Cl. 51-170) This invention relates to a polishing device andmore particularly to a portable device for polishing spots on metallicand other surfaces which are to be examined under the reflected lightmicroscope. To make such examination the material must be polished andetched with an acid to reveal the crystalline structure. The polishingshould not distort the structure by cold working and should not leavescratches or cause pitting or other deformation and it should notenlarge or fill in the voids which may exist. It should be capable ofremoving any surface or skin layers which are not to be examined.

Conventionally, such process is accomplished by cutting a small samplefrom the metal and taking it to a laboratory where it is abradedmanually or mechanically against successively finer grades of abrasiveson rotating wheels. The sample is moved around the wheel so that thedirection of abrasion changes constantly. If done by hand the directionis changed by different directional movements of the hand.

However, it is sometimes desirable to polish and examine a spot on alarge article which cannot be moved or may not be destroyed, such aslarge castings, pipes, tanks, welded joints or the like.

It is, therefore, an object of the present invention to provide aportable apparatus which can accomplish polish ing of a spot to beexamined under a microscope on the situs of the object to be inspectedwithout cutting a piece thereof or examining it in places where theremoval of a section would be destructive.

The device of the present invention may be rested on top of a horizontalor substantially horizontal surface by means of tripod legs. Instead ofthe legs it may be attached by suitable means to vertical, upside-down,inclined or other surfaces and the polishing accomplished in situ.

The portable spot polisher of the present invention comprises a spindlecarrying a resilient flexible polisher head and is rotated by suitablemeans simultaneously about its axis and in a gyratory movement, or morespecifically in an orbital path on the fixed surface to be polished in aconvenient and economical manner.

Other objects and advantages of the present invention, its details ofconstruction and arrangement of parts, will be apparent from aconsideration of the following specification and accompanying drawingswherein:

FIG. 1 is a perspective view of the device of the present inventiondisposed vertically on tripod legs.

FIG. 2 is a longitudinal section of the device shown in FIG. 1 and inlieu of the legs of FIG. 1 the device of FIG. 2 is provided with anadapter which permits the polisher to be used either vertically with itspolishing head down, or vertically with its polishing head up, or inhorizontal or inclined positions.

FIG. 3 is a transverse section on the line 33 of FIG. 2.

FIG. 4 diagrammatically indicates the orbital movement of the polisherhead of the present invention, and

FIG. 5 diagrammatically indicates the abrading pattern or action of thespot polishing device of the present invention.

FIG. 6 is a perspective view of the polishing head showing the separableabrasive or polishing cloth attached thereto.

Referring to the drawings, the reference numeral 10 3,284,961 PatentedNov. 1 5, 1966 indicates a two-piece substantially cylindrical outerhousing suitably composed of two sections having annular flanges joinedtogether by bolts as at 11. Concentrically disposed within this outerhousing is the inner housing 12. This inner housing 12 is rotatablymounted within the outer housing 10 by means of the bearing 13 disposedbetween the forward end portions 14 and 15 at one end of the assembly,and at the other end by means of the bearing 16 which journals the shaft17 secured to the end plate 18 integral with the inner housing 12.

Disposed within the inner housing -12 and at an incline of about 25 toits longitudinal axis is a motor generally indicated as 19. This motoris fixedly seated at one end by means of its boss 20 lodged in theintermediate plate 21 extending transversely in the inner housing 12,and at its opposed or forward end by means of the boss 22 disposedwithin the annular seat 23 integral with the forward end or head of thehousing 1 2.

One end of the armature shaft 24 has secured thereto a chuck 25 whichcarries the axially reciprocal resiliently mounted or spring-pressedspindle 26. The spindle in turn has removably secured therein a flexibleresilient polisher head 27 to which there is adhesively and releasablysecured abrasive paper or other polishing material 28.

For operation in the field this motor 19 may be a 12 volt DC. motor andoperated from a source such as .a battery, rectifier or generator. Thecurrent is fed to the battery through the line or cord 29 controlled bythe On-Of'f switch 30, and leads to a pair of annular brass rings 31, 32seated in the hardened resinous holder, such as a phenolic composition33, within an annular recess in the dome 34 of outer housing 10. Thecurrent is picked up from the rings 31 and 32 by means of thespring-pressed brushes 35 and 36 leading to the motor field through theleads 37.

The inner housing 12 and its fixedly secured, angularly disposed, motor19 are caused to jointly rotate by means of the rubber surfaced frictionwheel 38- in engagement wit-h the dome 34 and operatively securedthrough reduction gearing to the motor armature shaft end 39 whichcarries the pinion gear 40. This gear train consists of the gear 41engaged to the gear 40', which in turn carries the pinion gear 42 meshedwith the gear 43. The latter carries a pinion gear 44 which in turnmeshes with the gear 45 of the shaft 46 which is supported in thebushing 47 seated in'the transverse plate 21 in the inner housing 12.The shaft 46 extends through an opening in the head 18 of inner housing12 and supports the friction wheel 38 in operative engagement with theinner periphery of the dome 34 of outer housing 10 .as previouslydescribed. Thus, when the motor 19' is actuated, its spindle 26 willrotate at for example 5,000 r.p.-m., whereas the spindle 26 and itsattached polisher head 27 will gyrate about the axes of the housings 10and 12 in an orbital pat-h at a much lesser speed.

The assembly may be vertically disposed over the work to be polished bymeans of the tripod legs 48 which are in threaded engagement with thelower section of the outer housing 10, as at 49, this threadedengagement permitting vertical adjustment of the unit with respect tothe surface to be polished.

In lieu of the tripod legs 48 an adapter may be provided comprising anarm 50 as shown in FIG. 2, which snugly embraces the outer housing 10and is held engaged by the standard 51 over the aperture plate 52 whereit may be adjusted longitudinally of the standard 51 by means of thespring 54. The plate 52 may be engaged to the work by suitable clamps,chains, or other means not shown.

FIG. 4 diagrammatically indicates the orbital path of the polishing head27. As will appear from the illustrations, when the head 27 contacts thework its entire surface is not in contact therewith but ratherapproximately one-half the area thereof. As this rotates in its orbitalpath the overlapping pattern causes polishing of a rela: tively smallarea indicated at 55 shown within the dotted circle in FIG. 4.

FIG. 5 very diagrammatically indicates the polishing pattern of thepresent invention and shows in a linear manner superimposedsemi-circular patterns showing their multitudinous overlap of the spot55 being polished. Actually, the movement instead of being rectilinearas shown in the semi-circular portions is curvilinear, and the grindingaction comes from all directions during a complete circuit of thepolishing head 27. By successively reducing the fineness of the abrasivepad 28, and through the .aid of liquids for suspending polishingmaterials as is conventional in the art to which the present inventionpertains, ultimately a highly polished spot ready for microscopicexamination is obtained.

Although I have shown and described the preferred embodiment of myinvention, it -wil be understood by those skilled in the art thatchanges may be made in the details thereof without departing from itsscope as comprehended by the following claims.

I claim:

1. A portable spot polisher comprising .an outer ho-using adapted to besupported adjacent to a surface to be polished, an inner concentrichousing rotatably mounted within said outer housing, a motor fixedlysecured to and within said inner housing and at an angle to thelongitudinal axis of said inner housing, means for rotating said innerhousing and motor operatively associated with one end of the motor shaftand disposed within said outer housing and a spindle carrying aresilient flexible polisher head engaged to the opposed end of the motorshaft and projecting outwardly through aligned apertures formed in saidhousings.

2. A portable spot polisher comprising an outer housing, means forsupporting said housing adjacent to a surface to be polished with itslongitudinal .axis normal to said surface, an inner concentric housingrotatably mounted within said outer housing, a motor fixedly secured toand within said inner housing and at an angle to the longitudinal axisof said inner housing, means for rotating said inner housing and motoroperatively associated with one end of the motor shaft and disposedWith-in said outer housing and a yieldably urged axially reciprocablespindle carrying a resilient flexible polisher head engaged to theopposed end of the motor shaft and projecting outwardly through alignedapertures formed in said housings.

3. A portable spot polisher comprising an outer housing adapted to besupported adjacent and normal to a surface to be polished, an innerconcentric housing rotatably mounted within said outer housing, a motorfixedly secured to and within said inner housing with its axis at anangle to the longitudinal axis of said inner housing, frictional drivemeans for rotating said inner housing and motor operatively associatedwith one end of the motor shaft and disposed within said outer housingand a spindle carrying a resilient flexible polisher head engaged to theopposed end of the motor shaft and projecting outwardly through alignedapertures formed in said housings.

4. A portable spot polisher comprising an outer housing adapted to besupportedadjacent and normal to a surface to be polished, an innerconcentric housing rotatably mounted within said outer housing, a motorfixedly secured to and within said inner housing with its axis at anangle to the longitudinal axis of said inner housing, frictional drivemeans for rotating said inner housing and motor disposed within saidouter housing and operatively associated with one end of the motor shaftthrough an interposed speed reducing gear train, and a spindle carryinga resilient flexible polisher head engaged to the opposed end of themotor shaft and projecting outwardly through aligned apertures formed insaid housings.

References Cited by the Examiner UNITED STATES PATENTS 1,519,526 12/1924 Bean 51-43 1,622,592 3/1927 Kartz 5ll70 1,996,842 4/1935 Stevens51-43 2,303,531 12/ 1942 Eyster 51-120 2,942,3 84 6/ 1960 Higley 51-17023,205,622 9/1965 Leveque 51120 FOREIGN PATENTS 627,428 6/ 1927 France.

373,465 4/1923 Germany.

324,583 l/1930 Great Britain.

HAROLD D. WHITEHEAD, Primary Examiner.

1. A PORTABLE SPOT POLISHER COMPRISING AN OUTER HOUSING ADAPTED TO BESUPPORTED ADJACENT TO A SURFACE TO BE POLISHED, AN INNER CONCENTRICHOUSING ROTATABLY MOUNTED WITHIN SAID OUTER HOUSING, A MOTOR FIXEDLYSECURED TO AND WITHIN SAID INNER HOUSING AND AT AN ANGLE TO THELONGITUDINAL AXIS OF SAID INNER HOUSING, MEANS FOR ROTATING SAID INNERHOUSING AND MOTOR OPERATIVELY ASSOCIATED WITH ONE END OF THE MOTOR SHAFTAND DISPOSED WITHIN SAID OUTER HOUSING AND A SPINDLE CARRYING ARESILIENT FLEXIBLE POLISHER HEAD ENGAGED TO THE OPPOSED END OF THE MOTORSHAFT AND PROJECTING OUTWARDLY THROUGH ALIGNED APERTURES FORMED IN SAIDHOUSINGS.